Proteomic Analysis of Domestic Cat Blastocysts and Their Secretome Produced in an In Vitro Culture System without the Presence of the Zona Pellucida

Domestic cat blastocysts cultured without the zona pellucida exhibit reduced implantation capacity. However, the protein expression profile has not been evaluated in these embryos. The objective of this study was to evaluate the protein expression profile of domestic cat blastocysts cultured without the zona pellucida. Two experimental groups were generated: (1) domestic cat embryos generated by IVF and cultured in vitro (zona intact, (ZI)) and (2) domestic cat embryos cultured in vitro without the zona pellucida (zona-free (ZF group)). The cleavage, morula, and blastocyst rates were estimated at days 2, 5 and 7, respectively. Day 7 blastocysts and their culture media were subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The UniProt Felis catus database was used to identify the standard proteome. No significant differences were found in the cleavage, morula, or blastocyst rates between the ZI and ZF groups (p > 0.05). Proteomic analysis revealed 22 upregulated and 20 downregulated proteins in the ZF blastocysts. Furthermore, 14 proteins involved in embryo development and implantation were present exclusively in the culture medium of the ZI blastocysts. In conclusion, embryo culture without the zona pellucida did not affect in vitro development, but altered the protein expression profile and release of domestic cat blastocysts.

A Subovulatory Dose of Human Chorionic Gonadotropin (hCG) May Sustain Terminal Follicle Development and Reproductive Efficiency during Anestrus in Sheep

The study tested the hypothesis that a single administration of hCG supports the LH-dependent phase of terminal follicular development in synchronized sheep during anestrus, using eCG as a functional reference. Using a clinical approach, four experiments were designed to achieve the following: (1) Identify the inhibitory influence of anestrus on reproduction efficiency; (2) Assess the potential of hCG to keep functional blood concentrations after a single dose; (3) Characterize the effect of different doses of hCG on reproductive functional markers; (4) To compare the ability of hCG to that of eCG to support follicular development and fertility based on the same markers. The results showed that anestrus seems to affect follicular and luteal function under LH dependency as FSH-dependent markers are not compromised; hCG maintains higher blood concentrations than controls for at least 48 h; hCG improves follicular development and ovulatory rates compared to controls and at standards comparable to a breeding season; and ewes treated with hCG exhibit similar performance to those treated with eCG. Our results conclude that hCG can be used to support follicular function during anestrus in sheep, aiming to perfect its regulation in assisted reproduction.

Unveiling the Role of IGF-I in Fertility: Effect of Long-Acting Bovine Somatotropin (bST) on Terminal Follicular Development and Fertility during an Annual Reproductive Cycle in Sheep

The study aimed to assess the effect of long-acting bST treatment, in a dose that only increases IGF-I plasma concentrations, on ovarian and fertility markers of estrous synchronized ewes that were fed to keep their bodyweight. Three experiments were designed to evaluate this effect: in Experiment 1, 18 ewes were distributed in groups (bST 0, 30, 50 mg) to measure plasma IGF-I and insulin for 15 days; in Experiment 2, 92 ewes (5 replicates) in two groups (0 and 30 mg bST) were synchronized using a 6-day progesterone protocol during the breeding season to assess the effect of bST on follicular and luteal performances, estrous and ovulation, and fertility after mating. In Experiment 3, 50 ewes (3 replicates) were used to repeat the study before but during anestrus. Results indicate that 50 mg bST increased IGF-I and insulin plasma concentrations, but 30 mg bST only increased IGF-I concentrations; and that only during the breeding season did 30 mg bST increase the number of lambs born and the reproductive success of ovulatory-sized follicles compared to controls. This occurred without it affecting any other reproductive marker. In conclusion, 30 mg bST treatment may improve oocyte competence for fertility during the breeding season.

Loss of Direct Vascular Contact to Astrocytes in the Hippocampus as an Initial Event in Alzheimer's Disease. Evidence from Patients, In Vivo and In Vitro Experimental Models

Alzheimer's disease (AD) is characterized by the accumulation of aggregated amyloid peptides in the brain parenchyma and within the walls of cerebral vessels. The hippocampus-a complex brain structure with a pivotal role in learning and memory-is implicated in this disease. However, there is limited data on vascular changes during AD pathological degeneration in this susceptible structure, which has distinctive vascular traits. Our aim was to evaluate vascular alterations in the hippocampus of AD patients and PDAPP-J20 mice-a model of AD-and to determine the impact of Aβ40 and Aβ42 on endothelial cell activation. We found a loss of physical astrocyte-endothelium interaction in the hippocampus of individuals with AD as compared to non-AD donors, along with reduced vascular density. Astrocyte-endothelial interactions and levels of the tight junction protein occludin were altered early in PDAPP-J20 mice, preceding any signs of morphological changes or disruption of the blood-brain barrier in these mice. At later stages, PDAPP-J20 mice exhibited decreased vascular density in the hippocampus and leakage of fluorescent tracers, indicating dysfunction of the vasculature and the BBB. In vitro studies showed that soluble Aβ40 exposure in human brain microvascular endothelial cells (HBMEC) was sufficient to induce NFκB translocation to the nucleus, which may be linked with an observed reduction in occludin levels. The inhibition of the membrane receptor for advanced glycation end products (RAGE) prevented these changes in HBMEC. Additional results suggest that Aβ42 indirectly affects the endothelium by inducing astrocytic factors. Furthermore, our results from human and mouse brain samples provide evidence for the crucial involvement of the hippocampal vasculature in Alzheimer's disease.

Zona pellucida removal modifies the expression and release of specific microRNAs in domestic cat blastocysts

The in vitro culture of domestic cat embryos without the zona pellucida affects their implantation capacity. MicroRNAs (miRNAs) have an important role in embryo-maternal communication and implantation. The objective of this study was to evaluate the expression of specific miRNAs in domestic cat blastocysts cultured without the zona pellucida. Two experimental groups were done: (1) domestic cat embryos cultured with the zona pellucida (zona intact control group, ZI); and (2) cultured without the zona pellucida (zona free group, ZF). The cleavage, morula and blastocyst rates were evaluated. The blastocysts and their spent medium were used for miRNA expression analysis using RT-qPCR (miR-21, miR-24, mi25, miR-29, miR-96, miR-98, miR-103, miR-191, miR-196, miR-199, miR-130, miR-155 and miR-302). The pre-mature microRNAs (pre-miRNAs) and miRNAs were evaluated in the blastocysts and only miRNAs were evaluated in the spent medium. No differences were observed in the cleavage, morula and blastocyst rates between the ZF and ZI groups (P > 0.05). For miRNAs analysis, miR-103 and miR-191 had the most stable expression and were selected as internal controls. ZF blastocysts had a higher expression of miR-21, miR-25, miR-29 and miR-199 and a lower expression of miR-96 than their ZI counterparts (P < 0.05). Furthermore, higher levels of miR-21, miR-25 and miR-98 were detected in the spent medium of ZF blastocysts (P < 0.05). In conclusion, in vitro culture of domestic cat embryos without the zona pellucida modifies the expression of miR-21, miR-25, miR-29, miR-199 and miR-96 at the blastocyst stage and the release of miR-21, miR-25 and miR-98.

First molecular detection of Equine Herpesvirus type 3 (EHV-3) in Chile

Equine coital rash (ECE) is a highly contagious benign infection that induces lesions on external genitals, and it is caused by the equine herpesvirus type 3 (EHV-3). Although the disease is globally distributed, its presence in Chile has not been documented from a genetic point of view. Here, we performed polymerase chain reaction screenings for EHV-3 in lesions of external genitals in four horses belonging to a riding station at Bulnes, Ñuble Region, Chile. We sequenced a fragment of the glycoprotein G (gG) gene from three horses with clinical signs of ECE. The sequences were identical between them and 99.7% similar to a haplotype of EHV-3 detected in Brazil, and phylogenetically related with homologue from Japan, Russia and Brazil. Our results show the presence of EHV-3 for the first time in horses with ECE in Chile.

Domestic cat embryos generated without zona pellucida are capable of developing in vitro but exhibit abnormal gene expression and a decreased implantation rate

The removal of the zona pellucida has been used to improve the in vitro development of domestic cat embryos generated by IVF and SCNT. However, the in vivo development of domestic cat embryos generated without the zona pellucida has not been evaluated. The objective of this study was to evaluate the effects of zona pellucida removal on the in vitro and in vivo development of domestic cat embryos generated by IVF. For this purpose, two experimental groups were created: 1) domestic cat embryos cultured in vitro (Zona-intact group, ZI) and 2) domestic cat embryos cultured in vitro without the zona pellucida (Zona-free group, ZF). Domestic cat embryos were generated by IVF and cultured in vitro for 8 days. In the ZF group, the zona pellucida was removed after IVF, and embryos were cultured using the well of the well system (WOW). Cleavage, morula and blastocyst rates were evaluated in both groups. The diameter and total cell number of blastocysts were assessed. Relative expression of pluripotency (OCT4, SOX2 and NANOG), differentiation (CDX2 and GATA6) and apoptotic markers (BAX and BCL2) was evaluated in blastocysts. Finally, to evaluate in vivo development, embryos at days 5, 6 and 7 of development were transferred into recipient domestic cats, and ultrasonography was performed to evaluate implantation. No differences were observed in the cleavage, morula or blastocyst rates between embryos from the ZI and ZF groups. The diameter (mean ± SD) of blastocysts from the ZF group was greater (253.4 ± 83.3 μm) than that from the ZI group (210.5 ± 78.5 μm). No differences were observed in the relative expression of OCT4, CDX2 or GATA6. However, the relative expression of SOX2 and NANOG was significantly reduced in ZF blastocysts compared to ZI blastocysts. Furthermore, the relative expression of BAX was higher in ZF blastocysts than in ZI blastocysts. Finally, four pregnancies were confirmed after the transfer of ZI embryos (n = 110). However, no pregnancies were observed after the transfer of ZF embryos at the morula or blastocyst stage (n = 56). In conclusion, domestic cat embryos cultured without the zona pellucida were able to develop in vitro until the blastocyst stage. However, the removal of the zona pellucida negatively affected the gene expression of pluripotency and apoptosis markers, and ZF embryos were unable to implant. This might indicate that the removal of the zona pellucida is detrimental for the implantation and in vivo development of domestic cat embryos.

Distinctive Cellular Transcriptomic Signature and MicroRNA Cargo of Extracellular Vesicles of Horse Adipose and Endometrial Mesenchymal Stem Cells from the Same Donors

Equine endometrial and adipose mesenchymal stem cells (eMSCs and aMSCs, respectively) were isolated from the same donors of thoroughbred mares. The cells displayed characteristic features of MSCs, including trilineage mesodermal and also neurogenic differentiation. We evaluated the influence of cellular origin on their transcriptome profile. Cellular RNA was isolated and sequenced and extracellular vesicles (EVs) were obtained from conditioned medium of cells cultured in medium depleted of EVs, and their microRNA (miRNA) cargo analyzed by sequencing. Differential expression of mRNAs and EV-miRNA was analyzed, as well as pathways and processes most represented in each cell origin. mRNA reads from all expressed genes clustered according to the cellular origin. A total of 125 up- and 51 downregulated genes were identified and 31 differentially expressed miRNAs. Based on mRNA sequencing, endometrial MSCs strongly upregulated genes involved in the Hippo, transforming growth factor beta, and pluripotency signaling pathways. Alongside with this, pathways involved in extracellular matrix reorganization were the most represented in the miRNA cargo of EVs secreted by eMSCs. The niche from which MSCs originated defined the transcriptomic signature of the cells, including the secretion of lineage-specific loaded EV to ensure proper communication and homeostasis. Identification and testing their biological functions can provide new tools for the therapeutic use of horse MSC.

Assessment of the anti-inflammatory and engraftment potential of horse endometrial and adipose mesenchymal stem cells in an in vivo model of post breeding induced endometritis

Horse mesenchymal stem cells (MSC) are potential anti-inflammatory tools for post-breeding induced endometritis (PBIE). In this research MSCs isolated from the endometrium or subcutaneous fat of the same donors were infused iu into mares with PBIE for assessment of their anti-inflammatory action and engraftment. PBIE was induced in nine gynecologically healthy mares by iu infusion of 500 million dead sperm in saline. Inflammatory markers were analyzed in uterine lavages and biopsies immediately before (phase I) and 3 h after infusion of sperm (phase II). Measurements: polymorph nuclear cells (PMN), proteins IL-6 and TNFα (ELISA in the lavages) and immunostaining in biopsies, transcripts of IL-1α, 6, 8, 10, TNFα and COX2 (qPCR of pelleted lavages). At 24 h after sperm deposition (phase III), mares were instilled iu with 20 ml of saline containing 2 × 10⁷ adipose MSCs (n = 3, group 1) or endometrial MSCs (n = 3, group 2). Cells were labeled previously with carboxyfluorescein diacetate succinimidyl ester (CFDA SE). A third group (n = 3) received 20 mL of sterile saline alone. After 48 h another biopsy/lavage were done and the same parameters analyzed. For engraftment, additional biopsies were taken at days 10 and 30 of sperm infusion and analyzed by confocal microscopy. Dead sperm in saline markedly increased PMNs counts, IL-6 and TNFα expression in the ELISA (p < 0.05) and immunostaining. In phase III a significant reduction (p < 0.0001) of PMN was found in all samples, including control mares. A decrease (p < 0.05) of IL-6 and TNF-α was detected by ELISA, in the groups that received MSC, but not in control group. In the aMSC-treated group, a significant decrease was found in the expression of (IL1α, p = 0.0003; IL-6 p 0.04; IL-8, p = 0.006, TNFα p = 0.004). Expression of IL-10 and COX2 remained unchanged (p = 0.08). In the mares that received eMSC, IL-6 and 8 decreased significantly (p = 0.01), IL-10 increased (p = 0.009), while TNFα, COX2 and IL1α did not significantly change their expression. In the engraftment experiment CFDA label was found sparingly in all the samples analyzed until day 30, mainly at the stromal compartment of the endometrium. No differences in the engraftment pattern was found among cell origins. We conclude that inoculation of MSCs significantly reduced inflammation independently of the origin of the cells and that cells perform limited engraftment detectable after one month of infusion. These findings can be of help for the design of new anti-inflammatory therapies of uterine diseases in mares.

210 Horse allogeneic mesenchymal stem cells perform homing and ameliorate endometrial inflammation after induced endometritis of mares

Post-mating induced endometritis (PMIE) is an acute inflammatory response of the endometrium to spermatozoa, linked to an incapability of some mares to drain out the fluids associated with inflammation. This is of pivotal importance for reproductive success in mares. Mesenchymal stem cells (MSCs) are potential candidates for anti-inflammatory uterine therapies. Here, we aimed to study inflammatory markers in the endometrium of healthy mares and of those with induced endometritis, before and after intrauterine inoculation of MSCs, and to characterise their homing potential invivo in an induced endometritis horse model. Nine mares during their ovulatory season were selected after gynaecologic examination (absence of free liquid in the uterus, no polymorphonuclear leucocytes (PMNs) at cytology, negative bacteriology, and grade I in Kenney's scale on uterine biopsies). Mares were infused in the uterine body with 2mL of 500×106 spermmL−1 previously killed by repeated frozen-thawing cycles. At 3h, uteri were flushed with 250mL of sterile saline and the inflammatory response was monitored in the lavages and biopsies. Parameters measured included cytology, protein expression of inflammatory markers (supernatant) after lavage centrifugation (800×g, 10min), ELISA, and immunostaining for interleukin (IL)-6 and tumor necrosis factor alpha (TNFα). The mares were divided into three groups (3 mares each). Then, 24h after dead sperm challenge, group 1 received intrauterine infusion of 2×107 adipose MSC in 0.9% sterile saline; group 2, received the same amount of endometrial MSCs in the same vehicle; and group 3 received only saline. The volume of infusion in the uterine body was 20mL for all groups. Cells (passage 4) were previously labelled with 10μM Vybrant CFDA SE Cell Tracer Kit (ThermoFisher Scientific). After 48h, the same lavages, biopsies, and measurements as described above were performed. Additional biopsies were taken at Days 10 and 30 after intrauterine infusions. Biopsies were split in two, one for confocal microscopy and the other for quantitative PCR. Endometritis was induced in all mares, as judged by cytology and expression of protein markers of inflammation. After 48h, reduction in IL-6 and TNFα was detected by immunostaining of biopsies and confirmed by ELISA in the lavages, as well as by PCR. Homing was detected in all mares infused with MSC and it persisted at Days 10 and 30 after infusion. No homing was found in the control mares. As a result of these experiments, we conclude that inoculation of MSCs significantly reduced inflammation independently of the origin of the cells (adipose or endometrial). Both types of cells were nested in the endometrium at low quantities, although the number of cells actually detected at fixed time points was not quantified. Overall, we can propose that, given the number of homed cells detected and the marked decrease in inflammatory markers after inoculation of cells, MSCs exert their anti-inflammatory function preferentially by a paracrine mechanism and not necessarily by nesting and proliferation, although both events occur. Funding for this study was provided by Fondecyt 1150757.

128 Next-generation RNA sequencing of horse adipose and endometrial mesenchymal stem cells from the same donors unveils striking differences in their transcriptomic pattern

Earlier we successfully isolated and characterised endometrial (eMSC) and adipose (aMSC) mesenchymal stem cells from the same donors. Mesenchymal stem cells share biological traits but display different surface marker phenotype and migration ability. Here we extended our research to their mRNA signature using next-generation sequencing. The RNA from cells (3 biological replicates from each cell type and 3 technical replicates) at 90% confluence was extracted using a total RNA extraction kit and sent for mRNA-Seq (Norgen, Ontario, Canada; Illumina Sequencing Platform NextSEqn 500). Raw 76-bp single-end reads were aligned against the EquCab3 genome using RNA-STAR aligner. Counts were filtrated at a minimum of 5. Pairwise comparisons between the cell types were the input for gene ontology enrichment analysis. Only genes differentially expressed (DE) with 5 folds change (FC; P&lt;0.05) were analysed. For DE analysis, eMSC were set as control and compared with aMSC. Unsupervised hierarchical clustering of the global gene expression signatures was done to compare the samples from each line using principal component analysis (PCA) and EdgeR: v3.20.9. Gene expression was normalized using FPKM. The heat map was built using R studio with G-plot package. A total of 14,896 transcripts with at least 5 reads were found; of these, 1598 were DE: 627 up-regulated (FC range: 2 to 236×) and 971 down-regulated (FC range: 2 to 464×) in eMSC. There was a marked dispersion in the FC of up- and down-regulated genes (&gt;50×: 8 and 13; &gt;20×, &lt;50×: 9 and 17; &gt;10×, &lt;20×: 29 and 63; &gt;5×, &lt;10×: 91 and 130 and &gt;2×, &lt;5×: 490 and 748, respectively). Only genes DE with FC at least 5× were used for gene ontology and PCA analysis. Though 14,058 genes were common to both cell types, specific set of genes were found only in eMSC (n=162) or aMSC (n=676). Among the top 50 genes overexpressed in eMSC, several genes key for stem cell growth, immune response, migration and angiogenesis were found: TRIL, CXCL8, PDGF-D, SEMA5A, PTGS2, FGD, LAMA2, IL36G. In the top 50 down-regulated genes, some pivotal for osteoblast, adipogenic and neural differentiation were dramatically down-regulated (GPM6B, SCARA5 and NOTCH3 or NEFM, respectively), but no genes involved in immune rejection or stem cell proliferation were found. In gene ontology, the categories represented the most were cellular, developmental, metabolic, and immune system processes, as well as biological regulation, response to stimuli, organellar biogenesis, locomotion, localization and biological adhesion. Heat map and PCA analysis showed that one individual cell line from each type diverged markedly from the shared pattern. Individual variability of the donors may impinge upon the results; nevertheless, striking differences in the mRNA portfolio of eMSC and aMSC were detected. The importance and potential biological role of several of the genes and processes named above will be discussed in detail elsewhere. This work was supported by grant FONDECYT REGULAR 1150757 and the Government of Chile.

Effect of bST administration on plasma concentrations of IGF-I and follicular dynamics and ovulation during the interovulatory cycle of sheep and goats

This study used a comparative approach to gather clinical information to assess the effect of bovine somatotropin (bST) on follicular dynamics and ovulation in sheep and goats during an interovulatory cycle. The performance of general markers of ovarian function and specific features of follicular dynamics obtained by daily ultrasonography (US) were used to assess the hypothesis that bST, associated with supraphysiological levels of IGF-I, was able to disrupt the follicular dynamics and ovulation in Highlander ewes and Saanen goats. In Exp 1, 15 ewes and 14 goats were estrous-synchronized (P₄-6 days + PGFα d-6) and then allocated to a bST-treated group (50 and 100 mg, Lactotropin^®; n = 5 females each) and to an untreated control group (5 ewes and 4 goats) to assess the activity of bST through plasma IGF-I (RIA). In Exp 2, 12 animals from each species were synchronized. At day 6, they were divided into a bST-group (100 mg in sheep and 50 mg in goats, n = 6 each) and an untreated control group (n = 6 each). Starting at day 6 and up to 22 days after ovulation in sheep and 25 days in goats, each female was subjected to daily US (10 mHz probe) to assess follicular and luteal (CL) dynamics and ovulation. This included assessments of both general ovarian features and specific follicular wave features. Our results showed that bST increased plasma IGF-I by day 3 (p < 0.01) when compared to the control group. Moreover, these concentrations were maintained for at least 10 days in sheep and 10 days in goats before returning to pre-treatment concentrations. Increases in IGF-I after bST doses were similar in terms of a daily and total amount (P > 0.10). Results from Exp.2 indicate that in sheep, bST administration had a subtle inhibitory effect on follicular function. However, bST in goats had a stronger influence, extending the interovulatory cycle (P = 0,034), increasing the number of follicular waves during the period (P = 0.003), and reducing the functional potential of large follicles as measured by their lower follicular diameter (P = 0.02), duration of the follicle waves (P = 0.02), and persistence of follicles after reaching their maximum diameters (P = 0.04). In addition, untreated sheep and goats shared common patterns of terminal follicular development and ovulations characterized by overlapping between follicular waves and ovulations of follicles from different waves, features not seen in cattle.

Equine mesenchymal stem cells derived from endometrial or adipose tissue share significant biological properties, but have distinctive pattern of surface markers and migration

Adult stromal mesenchymal stem cells (MSCs) have been postulated as responsible for cell renewal in highly and continuously regenerative tissues such as the endometrium. MSCs have been identified in the endometrium of many species including humans, rodents, pets and some farm animals, but not in horses. The objective of this work was to isolate such cells from the endometrium of mares and to compare their main biological attributes with horse adipose-derived MSCs. Here we successfully isolated and characterized endometrial MSCs (eMSCs) from mares. Said cells showed fibroblast-like morphology, grew on plastic, had doubling population times of 46.4 ± 3.38 h, underwent tri-lineage (osteo, chondro and adipogenic) differentiation after appropriate inductions, migrated toward the attraction of fetal calf serum and displayed a pattern of surface markers commonly accepted for horse MSCs. All these are properties of MSCs. Some of these attributes were shared with equine adipose-derived MSCs, but the migration pattern of eMSC at 12 and 24 h after stimulation was reduced in comparison with adipose MSCs. Also, expression of CD44, CD90 and MHCI surface markers were dramatically down-regulated in eMSCs. In conclusion, equine-derived endometrial MSC share biological attributes with adipose MSC of this species, but displayed a different surface marker phenotype and an impaired migration ability. Conceivably, this phenotype is distinctive for MSC of this origin.

Sphingosine-1-phosphate restores endothelial barrier integrity in ovarian hyperstimulation syndrome

STUDY QUESTION

Are follicular fluid (FF) sphingosine-1-phosphate (S1P) levels in patients at risk of developing ovarian hyperstimulation syndrome (OHSS) altered and in part responsible for the high vascular permeability observed in these patients.

STUDY ANSWER

FF S1P levels are lower in FF from patients at risk of OHSS and treatment with S1P may reduce vascular permeability in these patients.

WHAT IS KNOWN ALREADY

Although advances have been made in the diagnosis, and management of OHSS and in basic knowledge of its development, complete prevention has proven difficult.

STUDY DESIGN, SIZE, DURATION

A total of 40 FF aspirates were collected from patients undergoing ART. The women (aged 25-39 years old) were classified into a control group (n = 20) or a group at risk of OHSS (n = 20). The EA.hy926 endothelial cell line was used to assess the efffects of FF from patients at risk of OHSS with or without the addition of S1P. An animal model that develops OHSS in immature Sprague-Dawley rats were also used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Migration assays, confocal microscopy analysis of actin filaments, immunoblotting and quail chorioallantoic membrane (CAM) assays of in-vivo angiogenesis were performed and statistical comparisons between groups were made.

MAIN RESULTS AND THE ROLE OF CHANCE

The S1P concentration was significantly lower in FF from patients at risk of OHSS (P = 0.03). The addition of S1P to this FF decreased cell migration (P < 0.05) and prevented VE-cadherin phosphorylation in endothelial cells (P < 0.05). S1P in the FF from patients at risk of OHSS increased the levels of VE-cadherin (P < 0.05), N-cadherin (P < 0.05) and β-catenin (P < 0.05), and partially reversed actin redistribution in endothelial cells. The addition of S1P in FF from patients at risk of OHSS also decreased the levels of vascular endothelial growth factor (VEGF₁₂₁; P < 0.01) and S1P lyase (SPL; P < 0.05) and increased the levels of S1PR1 (P < 0.05) in endothelial cells. In CAMs incubated with FF from patients at risk of OHSS with S1P, the number of vessel branch points decreased while the periendothelial cell coverage increased. Additionally, in a rat OHSS model, we demonstrated that vascular permeability and VEGF₁₂₁ and its receptor KDR expression were increased in the OHSS group compared to the control group and that S1P administration decreased these parameters.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The results of this study were generated from an in-vitro system. This model reflects the microvasculature in vivo. Even though the ideal model would be the use of human endothelial cells from the ovary, it is obviously not possible to carry out this kind of approach in ovaries of patients from ART. More studies will be necessary to delineate the effects of S1P in the pathogenesis of OHSS. Hence, clinical studies are needed in order to choose the most appropriate method of prevention and management.

WIDER IMPLICATIONS OF THE FINDINGS

The use of bioactive sphingolipid metabolites may contribute to finding better and safer therapeutic strategies for the treatment of OHSS and other human diseases that display aberrant vascular leakage.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants ANPCyT (PICT 2012-897), CONICET (PIP 5471), Roemmers and Baron Foundation, Argentina. The authors declare no conflict of interest.

The autophagic- lysosomal pathway determines the fate of glial cells under manganese- induced oxidative stress conditions

Manganese (Mn) overexposure is frequently associated with the development of a neurodegenerative disorder known as Manganism. The Mn-mediated generation of reactive oxygen species (ROS) promotes cellular damage, finally leading to apoptotic cell death in rat astrocytoma C6 cells. In this scenario, the autophagic pathway could play an important role in preventing cytotoxicity. In the present study, we found that Mn induced an increase in the amount and total volume of acidic vesicular organelles (AVOs), a process usually related to the activation of the autophagic pathway. Particularly, the generation of enlarged AVOs was a ROS- dependent event. In this report we demonstrated for the first time that Mn induces autophagy in glial cells. This conclusion emerged from the results obtained employing a battery of autophagy markers: a) the increase in LC3-II expression levels, b) the formation of autophagic vesicles labeled with monodansylcadaverine (MDC) or LC3 and, c) the increase in Beclin 1/ Bcl-2 and Beclin 1/ Bcl-X(L) ratio. Autophagy inhibition employing 3-MA and mAtg5(K130R) resulted in decreased cell viability indicating that this event plays a protective role in Mn- induced cell death. In addition, mitophagy was demonstrated by an increase in LC3 and TOM-20 colocalization. On the other hand, we proposed the occurrence of lysosomal membrane permeabilization (LMP) based in the fact that cathepsins B and D activities are essential for cell death. Both cathepsin B inhibitor (Ca-074 Me) or cathepsin D inhibitor (Pepstatin A) completely prevented Mn- induced cytotoxicity. In addition, low dose of Bafilomycin A1 showed a similar effect, a finding that adds evidence about the lysosomal role in Mn cytotoxicity. Finally, in vivo experiments demonstrated that Mn induces injury and alters LC3 expression levels in rat striatal astrocytes. In summary, our results demonstrated that autophagy is activated to counteract the harmful effect caused by Mn. These data is valuable to be considered in future research concerning Manganism therapies.

The endometrium of cycling cows contains populations of putative mesenchymal progenitor cells

Endometrial stem cells have been identified in humans, mice and pigs. This study was designed to determine whether the uterine endometrium of cycling cows contains such cells, to identify markers of stemness and ultimately to isolate putative stem/progenitor cell and evaluate their capability to differentiate into mesodermal derivatives. Uteri from healthy cows in the early (days 1-5) and late luteal phases (days 13-18) of the oestrous cycle were collected. Total RNA and proteins were isolated and searched for gene markers of embryonic (OCT4, NANOG, SOX2) and mesenchymal (CD44, STAT3, CD-117) stem cells and for protein markers (Oct4, Sox2, Cd44) in Western blots or immunostaining of paraffin-embedded tissue. Primary cell cultures were isolated; characterized in terms of morphology, colony formation and gene/protein expression; and induced osteogenic and chondrogenic differentiation. We identified expression of embryonic (OCT4 and SOX2, but not NANOG) and mesenchymal (STAT3, CD44 and c-KIT) gene markers in the endometrium of cycling cows and the encoded proteins (Oct4, Sox2 and Cd44) in both stages of the oestrous cycle. Derived cell lines displayed essentially the same gene expression pattern; however, at the protein level, Oct4 was not detected. No clear influence of the stage of the oestrous cycle was found. Cell lines from late luteal phase displayed osteogenic and chondrogenic differentiation potential upon chemical stimulation. In this research, we demonstrated the presence of mesenchymal progenitor cell populations of apparently mesenchymal origin in the endometrium of cycling cows, in both the early and late phases of the oestrous cycle. The cells isolated from the late luteal phase were more acquiescent to differentiate into mesodermal derivatives than cells in the early luteal phase. Our findings might have implications for the understanding of uterine stem cell biology in cows and other farm animal species.

184 ISOLATION AND CHARACTERIZATION OF BOVINE ENDOMETRIAL STEM CELLS

Adult mesenchymal stem cells had been isolated from various tissues of different species, including endometrial tissue of humans, mice, and pigs, but not from cattle. The aim of our work was to identify such cells in the bovine endometrium and to establish a model system in which to test inducers of differentiation and recruiters of stem cell niches, for potential therapeutic use in this and other species, such as horses. We searched for endometrial stem cells in healthy cycling cows and in cattle with clinical (C) or subclinical (SC) endometritis. For this, the uterine tracts of slaughtered cows were collected at early (Days 2 to 5; ELF) and late luteal phases (Days 11 to 15; LLF) of the oestrus cycle of healthy cows. For endometritis-diseased cattle, uterine biopsies were taken in live animals. In all cases, markers of stemness, inflammation, uterine function, and housekeeping were studied both at mRNA and protein level, by RT-qPCR and Western blot/immunohistochemistry respectively. In addition, cell primary cultures were established in vitro from all the animals (n = 4 for ELF, n = 4 for LLF; n = 4 for C and n = 4 for SC). We found that the endometrium of the majority of studied animals expressed embryonic stem cell markers, OCT4 and SOX2, but not or little NANOG, as well as CD44, c-Kit, and STAT3, all markers of mesenchymal stem cells. The expression profile of these markers was not related to the stage of the oestrus cycle; however there was a statistically significant reduction in the expression of embryonic stem cell markers in ill animals, being the lowest in clinically ill and intermediate in subclinical endometritis, (P < 0.05 and Pearson correlation coefficient 0.92). For markers of multipotency (mesenchymal), the expression was lower in clinical endometritis (P < 0.05). In conclusion, the expression profile of stem cell markers is indicative of the presence of stem cells in the bovine endometrium. At the protein level, we verified our findings for OCT4, SOX2, and CD44 using Western blot and immunohistochemistry. In general, there was a concordance between mRNA and protein profiles. Inflammatory markers showed a pattern characteristic for each of the studied stages. In order to have an ultimate criterion of the presence of stem cells, we tested the differentiation potential of the isolated cell lines, upon induction towards chondrogenic, osteogenic, and adipogenic lineages. We found that all the cell lines tested (n = 8) displayed mesenchymal differentiation potential as demonstrated by specific staining and gene expression markers. At present, work is in progress to isolate pure stem cell populations from these primary cultures to further characterise these cells. Conclusion: we showed for the first time the presence and differentiation potential of endometrial stem cells in cattle. This can have an effect on the development of new therapeutic approaches to combat uterine diseases, such as endometritis or endometriosis (in horses). This work was supported by grant FONDECYT REGULAR 1110642, from the Government of Chile.

Follicular dynamics, interval to ovulation and fertility after AI in short-term progesterone and PGF2α oestrous synchronization protocol in sheep

The study was aimed to assess the influence that short-term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7-day P4+PGF2α protocol using a new (n = 20) or a 7-day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short-term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p < 0.05) and exhibited a P4 peak at days 1-2 of the treatment that was not observed in ewes with used inserts. In Experiment 2, ewes treated with new and used inserts show similar ovarian and behavioral traits (p > 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment.

Spermadhesin PSP-I/PSP-II heterodimer induces migration of polymorphonuclear neutrophils into the uterine cavity of the sow

Seminal plasma (SP) is a complex fluid which exerts biological actions in the female reproductive tract. In pigs, SP elicits endometrial inflammation and consequent immune changes after mating. This study tested whether heparin-binding spermadhesins (HBPs) and the heterodimer of porcine sperm adhesions I and II (PSP-I/PSP-II) in SP recruit different lymphocyte subsets (CD2(+), CD4(+) and CD8(+) T cells) or polymorphonuclear leukocytes (PMNs) to the superficial endometrium or luminal epithelium and lumen, respectively, of oestrous sows. In Experiment 1, endometrial biopsies were taken between 2 and 120 min after infusion of uterine horns with HBPs, PSP-I/PSP-II or saline and evaluated by immunohistochemistry or histology. In Experiment 2, the uterus of oestrous sows was infused with PSP-I/PSP-II or saline to assess PMN numbers in the uterine lumen 3h later. PSP-I/PSP-II elicited CD2+ T cell recruitment from 10 min, and CD8(+) T cells from 60 min after infusion, while HBPs increased CD4(+) T cell recruitment by 120 min. PSP-I/PSP-II but not HBPs induced PMN migration to the surface epithelium by 10 min. PMN numbers were elevated 5-fold by 30 min and 7-fold from 60 min, with PMNs detectable in the lumen from 30 min after infusion. Six-fold more PMNs were collected from the uterine lumen of PSP-I/PSP-II-infused sows compared to controls at 3h after infusion. These data show that PSP-I/PSP-II heterodimer in seminal plasma has a predominant role in triggering the recruitment of uterine PMNs and T cells after mating, initiating a cascade of transient and long-lasting immunological events.

The vanguard sperm cohort of the boar ejaculate is overrepresented in the tubal sperm reservoir in vivo

In boars, sperm cohorts are sequentially emitted in epididymal cauda fluid and resuspended in different mixtures of accessory sex gland secretions while ejaculated in various fractions. During natural mating, these ejaculate fractions sequentially enter the cervix-uterine lumen, are quickly transported towards the tips of the uterine horns and colonize the oviductal sperm reservoirs (SR). Using a simple experiment, we tested the hypothesis that the first ejaculated sperm subpopulation (fortuitously present in the peak portion of the sperm-rich fraction [SRF], the so-called Portion 1, P1) is, by reaching first the SR, overrepresented there. Spermatozoa from P1- and of P2- (last portion of the SRF and the Post-SRF) were collected from 3 fertile boars. P1-spermatozoa were fluorophore DNA-stained, while P2-spermatozoa were kept unstained. Weaned estrous sows were conventionally inseminated (12 h after onset of estrus) with similar sperm numbers (approx 10 x 10(9) spermatozoa) per portion but in different orders as follows: (i) a mix of P1 and P2 aliquots (control, P1+P2, n=5), or testing (ii) a sequential order (P1-P2, Treatment A, n=5) or (iii) an inverse order (P2-P1, Treatment B, n=5) of cohort AI. Sows were euthanized approx 3 h post-AI, and the SRs were flushed to recover the spermatozoa, which were accounted for as stained or unstained. The total number of spermatozoa flushed did not differ between groups or boars (NS, ranging 0.9 to 2.0 x 10(9)). Sequential, in vivo-like, sperm deposition (P1-P2, Treatment A) yielded the highest proportion of stained P1-spermatozoa in the SRs (59.8 +/- 5.66%, means +/- SEM) compared with when the order was reversed (P2-P1, Treatment B; 15.6 +/- 2.1% P1-spermatozoa, P<0.05) or P1 and P2 sperm suspensions were mixed (control, 36.9 +/- 2.70% P1-spermatozoa, P<0.05). The tested hypothesis proved valid; if inseminated in the same order as ejaculated in vivo, P1-spermatozoa become overrepresented in the SR. The physiological consequences of this skewed SR-colonization are discussed in this paper alongside the advantageous use of P1-spermatozoa for handling, including cryopreservation.

Do cytoplasmic lipid droplets accumulate in immature oocytes from over-conditioned repeat breeder dairy heifers?

One of the main sources of repeat breeding in dairy cattle, caused by fertilization failure or early embryonic death, is metabolic stress during lactation. Nutrition seems also to play a role when the condition is seen in heifers, where oocyte cytoplasmic maturation is impaired. To determine whether over conditioning affects oocyte morphology, immature oocytes were collected by ovum pick-up (OPU) twice weekly during 5 weeks from three over-conditioned repeat breeder dairy heifers (RBH) and two normal virgin heifers (VH, controls) of the Swedish Red breed, monitored by body weight and condition. Oocyte quality was assessed under stereomicroscope and further examined by transmission electron microscope for accumulation of cytoplasmic lipid deposits. After OPU, the RBH yielded more low quality oocytes (60% vs 52% for VH, p = 0.14). The relative occupancy of osmophilic lipid droplets in the cytoplasm was higher in oocytes of bad quality compared with good ones, especially in RBH (p = 0.08) but also in VH (p = 0.11). Moreover, the oocytes from over-conditioned RBH showed higher amounts of cytoplasmic lipid deposits both in good (p = 0.14) and, even more prominent, in bad quality oocytes (p = 0.06). Such accumulation of lipid droplets may imply increased sensitivity to oxidative stress, hinder cytoplasmic maturation and lead to subfertility, as accounted in over-conditioned repeat breeders of the Swedish Red breed.

Selection of boar spermatozoa using centrifugation on a glycidoxypropyltrimethoxysilane-coated silica colloid

Use of sperm separation methods such as density gradient centrifugation for selecting the best spermatozoa for animal breeding is constrained by the problem of dealing with the large volumes of ejaculate produced by the males of some species, such as boars. The purpose of this study was to compare density gradient centrifugation (DGC) with centrifugation on a single layer of colloid (SLC) for the preparation of ejaculated boar spermatozoa using Androcoll(TM)-P. There was no difference between the two techniques in terms of sperm motility or duration of motility after selection, and sperm motility was retained for at least 24 h longer in the centrifuged sperm preparations than in controls (uncentrifuged aliquots). Sperm motility was significantly better (P<0.001) in the centrifuged sperm preparations (means +/- sd: SLC 79.6 +/- 8.1% and DGC 74.2 +/- 12.0%) than in the uncentrifuged controls (62.9 +/- 12.7%). The mean yield of motile spermatozoa for SLC was 67.5 +/- 25.6%, and for DGC it was 59.6% +/- 22.3% (not significant, ns). Sperm survival was significantly increased by colloid centrifugation (control 3.1 +/- 0.3 days, SLC 5.5 +/- 0.79 days, DGC 5.75 +/- 0.62 days; P<0.001 for uncentrifuged versus centrifuged; SLC vs. DGC, ns). Moreover, boar spermatozoa could be stored for 24 h before centrifugation without any detrimental effect on sperm motility or duration of motility. In a further experiment, larger volumes of ejaculate were processed easily on a modified SLC, indicating that this method may be practical for processing large volumes of boar ejaculates.

The physiological roles of the boar ejaculate

During ejaculation in the boar, sperm cohorts emitted in epididymal cauda fluid are sequentially exposed and resuspended in different mixtures of accessory sex gland secretion. This paper reviews the relevance of such unevenly composed fractions of seminal plasma (SP) in vivo on sperm transport and sperm function and how this knowledge could benefit boar semen processing for artificial insemination (AI). The firstly ejaculated spermatozoa (first 10 ml of the sperm-rich fraction, SRF [P1]) remain mainly exposed to epididymal cauda fluid and its specific proteins i.e. various lipocalins, including the fertility-related prostaglandin D synthase; than to prostatic and initial vesicular gland secretions. P1-spermatozoa are hence exposed to less bicarbonate, zinc or fructose and mainly to PSP-I spermadhesin; than if they were in the rest of the SRF and the post-SRF (P2). Since the P1-SP is less destabilizing for sperm membrane and chromatin, P1-spermatozoa sustain most in vitro procedures, including cryopreservation, the best. Moreover, ejaculated firstly, the P1-spermatozoa seem also those deposited by the boar as a vanguard cohort, thus becoming overrepresented in the oviductal sperm reservoir (SR). This vanguard SR-entry occurs before the endometrial signalling of SP components (as PSP-I/PSP-II and cytokines) causes a massive influx of the innate defensive PMNs to cleanse the uterus from eventual pathogens, superfluous spermatozoa and the allogeneic SP. The SP also conditions the mucosal immunity of the female genital tract, to tolerate the SR-spermatozoa and the semi-allogeneic conceptus. These in vivo gathered data can be extrapolated into procedures for handling boar spermatozoa in vitro for AI and other biotechnologies, including simplified cryopreservation.

Influence of seminal plasma on the kinematics of boar spermatozoa during freezing

Sperm motility is, for its relation to cell viability and fertility, a central component of the spermiogram, where consideration of motion patterns allows discrimination of sub-populations among boar spermatozoa. Extension and cryo-preservation imposes changes in these patterns in connection to handling, additives, temperature changes and the removal of boar seminal plasma (BSP) which apparently makes spermatozoa susceptible to oxidative stress, thus affecting survival and motility post-thaw. Detailed kinematic analyses during sperm cooling are sparse, particularly when considering the instrumentation and settings used for analyses, the effect of extenders, and of the BSP the processed spermatozoa are exposed to. Spermatozoa present in the first collectable 10mL of the sperm-rich fraction of the ejaculate (portion 1, P1-BSP), have shown an increased ability to sustain motility during and after cryo-preservation than spermatozoa immersed in the rest of the ejaculate (portion 2, P2). When P2-spermatozoa were cleansed from their BSP and exposed for 60min to pooled P1-BSP, their motility post-thaw increased to similar levels as P1-spermatozoa. This BSP-influence is sire-dependent, presumably related to the protein concentration in the different ejaculate portions, and apparently unrelated to changes in membrane integrity or membrane stability through conventional, controlled cooling.

GABAB receptors and glucose homeostasis: evaluation in GABAB receptor knockout mice

GABA has been proposed to inhibit insulin secretion through GABAB receptors (GABABRs) in pancreatic beta-cells. We investigated whether GABABRs participated in the regulation of glucose homeostasis in vivo. The animals used in this study were adult male and female BALB/C mice, mice deficient in the GABAB1 subunit of the GABABR (GABAB(-/-)), and wild types (WT). Blood glucose was measured under fasting/fed conditions and in glucose tolerance tests (GTTs) with a Lifescan Glucose meter, and serum insulin was measured by ELISA. Pancreatic insulin content and islet insulin were released by RIA. Western blots for the GABAB1 subunit in islet membranes and immunohistochemistry for insulin and GABAB1 were performed in both genotypes. BALB/C mice preinjected with Baclofen (GABABR agonist, 7.5 mg/kg ip) presented impaired GTTs and decreased insulin secretion compared with saline-preinjected controls. GABAB(-/-) mice showed fasting and fed glucose levels similar to WT. GABAB(-/-) mice showed improved GTTs at moderate glucose overloads (2 g/kg). Baclofen pretreatment did not modify GTTs in GABAB(-/-) mice, whereas it impaired normal glycemia reinstatement in WT. Baclofen inhibited glucose-stimulated insulin secretion in WT isolated islets but was without effect in GABAB(-/-) islets. In GABAB(-/-) males, pancreatic insulin content was increased, basal and glucose-stimulated insulin secretion were augmented, and impaired insulin tolerance test and increased homeostatic model assessment of insulin resistance index were determined. Immunohistochemistry for insulin demonstrated an increase of very large islets in GABAB(-/-) males. Results demonstrate that GABABRs are involved in the regulation of glucose homeostasis in vivo and that the constitutive absence of GABABRs induces alterations in pancreatic histology, physiology, and insulin resistance.

Brain alterations in autoimmune and pharmacological models of diabetes mellitus: focus on hypothalamic-pituitary-adrenocortical axis disturbances

Type 1 diabetes (T1D) is linked to an 'encephalopathy' explained by some features common to the aging process, degenerative and functional disorders of the central nervous system. In the present study we describe a manifest hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis in two different experimental mouse models of T1D including the pharmacological one induced by streptozotocin and the spontaneous NOD (nonobese diabetic mice). The high expression of hypothalamic hormones like oxytocin and vasopressin were part to this alteration, together with elevated adrenal glucocorticoids and prominent susceptibility to stress. In the hippocampus of diabetic animals a marked astrogliosis, often associated with neural damage, was present. Dentate gyrus neurogenesis was also affected by the disease: proliferation and differentiation measured by bromodeoxyuridine immunodetection were significantly reduced in both experimental models used. Several facts, including changes associated with chronic hyperglycemia, hyperstimulation of the HPA axis, increased levels of circulating glucocorticoids in combination with brain inflammation and low production of new neurons, contribute to emphasize the impact of diabetes on the central nervous system.

Controlled cooling during semen cryopreservation does not induce capacitation of spermatozoa from two portions of the boar ejaculate

Cryopreservation imposes dramatic changes in boar sperm survivability but it is as yet unclear which part of the process affects the spermatozoa the most. The present study monitored, along the entire process of cryopreservation, the stability (PMS) of the architecture of the lipid plasma membrane and its integrity (PMI), as well as the kinetics of the processed spermatozoa using two portions from the boar ejaculate (P1 = the first 10 mL of the sperm-rich fraction, SRF; P2 = the rest of the ejaculate), frozen in a recently developed package, the MiniFlatPack (MFPs, 0.5 x 10(9) sperm/dose). Evaluation was made at four specific stages, viz. S1 = after collection (suspended in Beltsville thawing solution, BTS); S2 = at 15 degrees C (suspended in lactose-egg yolk, LEY); S3 = at 5 degrees C (suspended in LEY plus glycerol); and S4 = post-thaw. Both sperm kinetics (using computer-assisted sperm analysis, CASA) and PMS [i.e. the degree of lipid disorder and of the exteriorization of phosphatidylserine (PS) in the plasma membrane, measured by flow cytometry using Merocyanine-540 (M-540), and Annexin-V (AV) respectively], as well as plasma membrane integrity [PMI, i.e. the degree of membrane damage, measured using Yo-Pro-1 or propidium iodide (PI)] were assessed after incubation in BTS at 38 degrees C. Moreover, spermatozoa were challenged by incubation in modified Brackett-Oliphant medium (mBO+) with 37 mm of bicarbonate at 38 degrees C for 30 min, and their PMS and PMI further explored. Total sperm motility was significantly higher in P1 than in P2 along the entire process (S1-S4; p < 0.01), decreasing significantly at S4 for both fractions (p < 0.0001). The proportion of spermatozoa showing linear motility (LinM) was similar between ejaculate portions (P1 and P2), with a significant increase post-thaw (S4; p < 0.0001). During cooling (S1-S3) but not post-thaw (S4), lateral head displacement (LHD) differed between portions and changed along the stages (p < 0.01). Sperm velocity differed between portions in S1 (p < 0.01), but remained similar, independently of the portion, thereafter (S2-S4). Both PMS and the total number of live spermatozoa remained similar between S1 and S3 while incubated in BTS for both ejaculate portions. Sperm mortality increased post-thaw (S4) in both portions but the degree of lipid disorder remained low in the live cells (1.28% for P1; 1.55% for P2). Exposure to mBO+, on the other hand, significantly increased membrane lipid disorder along cooling (S1-S3; p < 0.0001), increasing the percentages of dead spermatozoa, especially post-thaw (around 70%, both portions). PS-exteriorization (AV) was not evident along the cryopreservation process in control (BTS) samples and exposure to mBO+ only induced minor variations. The data showed that kinetics, PMS and PMI of boar spermatozoa suspended in BTS (S1), LEY (S2) or LEY plus glycerol (S3) were maintained during controlled cooling but were altered by thawing, showing more characteristics of cell injury than of sperm capacitation. The spermatozoa were able to capacitate but the bicarbonate challenge destabilized the plasma membrane during initial cooling and accelerated membrane changes post-thaw. We conclude that capacitation of boar spermatozoa does not occur during controlled cooling.

Post-thaw viability of bull AI-doses with low-sperm numbers

Use of AI-doses containing low-sperm numbers are increasingly been used to optimise use of elite bulls as well as to accommodate an eventual wider application of sex-sorted semen. Since spermatozoa might, however, suffer from high extension rates, thus compromising fertility, this study evaluated the post-thaw sperm quality of semen from commercial progeny-tested, high-ranked AI-sires whose semen was within acceptable limits of normality, frozen in a split-design to 15 (control, 15M) or 2 x 10(6) total spermatozoa (treatment, 2M) per straw. Assessment post-thaw included computer-evaluated sperm motility (CASA), membrane integrity (SYBR-14/PI), membrane stability (Annexin-V/PI), acrosome integrity (Carboxy-SNARF-1/PI/FITC-PSA), and chromatin integrity (AO of in situ acid-induced DNA denaturation). High extension did not affect the proportions of linearly motile spermatozoa, of membrane integrity or stability nor chromatin integrity, immediately post-thaw. However, high extension clearly affected linear sperm motility following incubation at 38 degrees C for 30 min, sperm viability when assessed by SNARF and, particularly, acrosome integrity of the otherwise viable spermatozoa. Individual sire variation was evident. Fertility was preliminarily evaluated for one of the less affected bulls in a blind field trial. A total of 109 dairy cows were randomly inseminated with 15M or 2M-straws without differences in pregnancy rate between them (47% versus 43%). This similarity in fertility rates, confirmed the in vitro methods used were appropriate for identifying cryosurvival and further suggested the site of sperm deposition was not crucial for the fertility of low-sperm AI-numbers for this particular sire. However, the inter-bull variation seen calls for caution when cryopreserving low concentrations of bull spermatozoa with conventional freezing protocols.

Effects of cryopreservation on semen quality and the expression of sperm membrane hexose transporters in the spermatozoa of Iberian pigs

This study evaluated the effects of cooling, freezing and thawing on the plasma membrane integrity, kinetics and expression of two sugar transporters glucose transporter-3 and -5 (GLUT-3 and GLUT-5) in spermatozoa from Iberian boars. Semen samples were collected twice weekly from eight young, fertile Iberian boars of the 'Entrepelado' and 'Lampiño' breeds. The samples were suspended in a commercial extender and refrigerated to 17 degrees C for transport to the laboratory (step A), where they were further extended with a lactose-egg yolk-based extender and chilled to 5 degrees C (step B) prior to freezing in the presence of glycerol (3%). Spermatozoa were assessed for plasma membrane integrity and sperm motility at each of the steps, including post-thaw (step C). Aliquots were also prepared for immunocytochemical localisation of the sugar transporters (fixed and thin smears for transmission and scanning electron microscopy levels respectively) and for SDS-PAGE electrophoresis and subsequent western blotting, using the same antibodies (rabbit anti-GLUT-3 and anti-GLUT-5 polyclonal antibodies). The results showed lower percentages of progressively motile spermatozoa at step C in both breeds, while the percentage of live spermatozoa was significantly lower only in the 'Entrepelado' breed. The results obtained from electron microscopy clearly showed that Iberian boar spermatozoa expressed the hexose transporters, GLUT-3 and GLUT-5. The pattern of expression, in terms of location and concentration, was characteristic in each case but, in the case of isoform GLUT-5, it remained constant during the different steps of freezing-thawing protocol. These results indicate that cryopreservation affects the status of sperm cells of Iberian boars by altering the distribution of some membrane receptors and decreasing the percentage values of parameters linked to sperm quality.

Differences in boar sperm head shape and dimensions recorded by computer-assisted sperm morphometry are not related to chromatin integrity

Although sperm head shape and relative dimensions are considered reliable indicators of sperm quality, their quantification is most often operator-driven, e.g., subjective. Artificial insemination semen doses from 35 mature stud boars of known fertility and belonging to three breeds and two hybrid breeds (Duroc, Large White, Landrace, respectively, Yorker and Risco) were used in this study. Sperm samples were extended to 100x10(6) cells per mL and 10microL of the sperm suspension used to made smears which, stained, were examined using phase contrast microscopy interfaced with an automated sperm morphology analyzer (ASMA, ISAS). Each sperm head was measured for four primary parameters [area (A) microm(2), perimeter (P) mum, length (L) microm, width (W) microm], and four derived parameters of head shape [(L/W), (4piA/P(2)), ((L-W)/(L+W)), (piLW/4A)]. Definition of head size was statistically performed. The threshold for each class was established on the basis of the area values, considering the 25th percentile as small and the 75th percentile as large spermatozoa. In a second step, sperm head shape was determined as normal, elliptic, abnormal (rugose) contour, long or irregular and percentiles set as above to define spermatozoa with normal values for each shape parameter. Significant differences were found among breeds in the size of morphologically normal spermatozoa, which were significantly larger and more elliptic (P<0.001) in the Duroc breed. Sperm chromatin integrity was studied using the SCSA-assay, with significant differences observed in the degree of fragmentation intensity (DFI) although this value was consistently low in all animals studied. The hereby-validated ASMA was able to determine significant differences in sperm shape and dimensions among breeds, which were not accompanied by deviations in chromatin structure neither within nor between fertile AI-boars.

Cryo-scanning electron microscopy (Cryo-SEM) of boar semen frozen in medium-straws and MiniFlatPacks

In this study we demonstrate, in the frozen state, the architecture of frozen boar spermatozoa collected from the sperm-rich fraction of ejaculates (n=13) from four fertile boars packed and split-frozen in medium-straws (MS) and MiniFlatPacks (MFP), cross-sectioned in the frozen state and evaluated by image analysis on images obtained by use of cryo-scanning electron microscopy (Cryo-SEM). The tested hypothesis was that the degree of in situ dehydration and levels of homogeneity of boar semen either frozen in MSs or MFPs packages differ between them, with MFPs allowing for a more uniform dehydration of the spermatozoa and a higher cryosurvival, monitored by computer assisted sperm analysis (CASA) as proportion of linearly motile spermatozoa, compared to semen packaged and processed in MSs. The organization and relative surface of biological material (veins; e.g., frozen extender, bound water, solutes and spermatozoa) as well as free water (lakes) was measured as the degree of dehydration of the samples. The apparent organization of lakes and veins differed between packages, with the MFPs depicting larger lakes than the MSs. The sizes of the lakes in the latter appeared, moreover, highly asymmetrical depending on their position of the section. The relative surface of these lakes per section, respectively veins differed between packages (P<0.05), indicating a larger amount of free-water (lakes; 81.73+/-2.07% vs. 77.91+/-1.57%) in the MFPs and, consequently, thinner veins than in MSs. In conclusion, MFPs seem to allow for a more homogenous dehydration of the spermatozoa/frozen extender compared to MSs, which might account for their somewhat better sperm quality post-thaw.

Differences in SCSA outcome among boars with different sperm freezability

Spermatozoa from some boars sustain the process of cryopreservation poorly and yield poor fertility after artificial insemination. Poor freezability has not been disclosed using conventional semen analyses. A defective chromatin can, if present in a substantial number of spermatozoa, affect the fertilizing ability of spermatozoa. Here we tested the hypothesis that nuclear DNA instability could explain differences in freezability among boars, and complement or supersede conventional tests for sperm quality such as sperm motility or membrane assessments. Frozen-thawed (FT) spermatozoa from a total of 44 stud boars were assessed by the sperm chromatin structure assay (SCSA), in relation to computer-assisted sperm analysis-derived sperm motility variables and sperm viability (triple fluorescent microscopic staining), including three experiments. The first trial, including 24 boars, evaluated the relationship between the sperm motility and viability with levels of DNA integrity. The SCSA showed that most spermatozoa had intact DNA [levels of DNA fragmentation index (%DFI) ranging from 0.63% to 11.85%] significantly correlated (albeit weakly) with current sperm quality variables. The second trial, on 15 boars, assessed the influence of two different thawing rates (20 s at 37 degrees C vs. 8 s at 70 degrees C) and the post-thaw incubation times (0, 30, 150 and 300 min) at 37 degrees C on FT-boar sperm quality. The highest sperm survival (p < 0.05) and the lowest DNA damage (p < 0.01) were achieved when thawing was carried out at 70 degrees C for 8 s, without any change during the first 150 min of incubation. Finally, the third experiment studied if differences in sperm freezability showed by stud boar semen, as 'good' or 'bad' freezers by conventional analyses, could be attributed to differences in chromatin structure. All SCSA parameters were low, but significantly (p < 0.05-0.001) higher for 'bad' freezers, showing they had less homogeneous sperm chromatin than the 'good' freezers. The results indicate that SCSA outcome complements conventional assessment of FT-boar spermatozoa, disclosing differences in their ability to sustain freezing and thawing. However, the low overall DNA damage observed in FT spermatozoa seems to have poor biological significance.

Does exposure to di(2-ethylhexyl) phthalate in pre-pubertal boars affect semen quality post-puberty?

Di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in polyvinyl chloride (PVC) products, has been ascribed to have toxic effects on animal reproduction. The present study aimed at determining potential late effects of pre-pubertal oral exposure to DEHP on semen quality in young pigs. Ten pairs of cross-bred male siblings were used. One brother in each pair became, at random, the test animal while the other acted as control. Test males were exposed to 300 mg/kg body weight (bw) of DEHP administered orally three times a week from 3 to 7 weeks of age. The control group was given placebo (water). Semen analyses started when the boars reached 6 months of age, with semen collected twice weekly, until animals were 9 months of age. Semen was evaluated for ejaculate volume, sperm concentration, total sperm count, sperm motility, sperm morphology (including presence of cells other than spermatozoa) and sperm plasma membrane integrity. Total sperm motility tended to be lower while local motility was higher in the DEHP-exposed group compared with controls (p = 0.07) when assessed by computer-assisted sperm analysis. The DEHP-exposed group had a significantly (p < 0.05) lower percentage of spermatozoa with tailless, defective heads (at 7-8 months of age) and double-folded tails (at 6-7, 7-8 and 6-9 months of age), compared with controls (albeit always under 5%). In summary, there were no obvious adverse effects of early oral exposure to 300 mg/kg bw of DEHP on sperm output and sperm quality in post-pubertal young boars.

Effect of storage in short- and long-term commercial semen extenders on the motility, plasma membrane and chromatin integrity of boar spermatozoa

For artificial insemination (AI) in pigs, preservation of liquid boar semen at 16-20 degrees C is still common practice as sperm cryopreservation remains suboptimal in this species. To meet the different needs of the swine industry, several extenders have been developed to preserve semen in liquid form for short--and long-term storage. In the present study, three different commercial extenders devised for short-term (BTS+) or long-term preservation (MR-A and X-Cell), were used to test whether storage of semen from four mature, fertile boars at 17 degrees C for 96 h would affect sperm characteristics relevant for fertility, such as motility, membrane integrity and chromatin stability. Computer-assisted sperm analysis, and stainings with the acylated membrane dye SYBR-14/propidium iodide, and acridine orange in connection with flow cytometry were used to evaluate these variables. Percentages of total motile spermatozoa decreased slightly, but significantly, after 72-96 h. While membrane integrity values varied during the period of study, no significant changes in either membrane integrity or chromatin stability were, however, registered. This suggests a customary 96-day storage at 17 degrees C in these extenders was too short an interval to cause losses of integrity in nuclear DNA in the boar population studied.

Effects of exposure of pre-pubertal boars to di(2-ethylhexyl) phthalate on their frozen-thawed sperm viability post-puberty

Late effects of pre-pubertal oral exposure to di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in, for example, polyvinyl chloride-products, on semen quality in young boars have not been clear-cut. The aim of this study was to determine whether stress imposed on spermatozoa would reveal such effects. Semen was collected from post-pubertal boars (8-9 months of age), which had been exposed to 300 mg kg(-1) body weight of DEHP per os three times a week from 3 to 7 weeks of age and from control siblings given placebo (water). The semen was cryopreserved and examined for plasma membrane integrity post-thaw using the short hypo-osmotic swelling test and flow cytometry (propidium iodide /SYBR-14). Sperm motility was assessed by computer-assisted sperm analysis. No significant difference in plasma membrane integrity could be found between the groups. The DEHP-exposed group had a significantly lower percentage of linearly motile spermatozoa at 30 min (P < 0.05) and 120 min (P < 0.001) after thawing, and a larger amplitude of lateral displacement of the head 120 min after thawing (P < 0.05), compared with controls. In summary, spermatozoa from boars pre-pubertally exposed to low doses of DEHP, showed kinematic deviations post-thaw that could be related to DEHP exposure.

Do different portions of the boar ejaculate vary in their ability to sustain cryopreservation?

Previous studies have shown sperm quality post-cryopreservation differs depending on the fraction of the seminal plasma boar spermatozoa are fortuitously contained in. As such, spermatozoa contained in the first 10 mL of the sperm-rich fraction (portion I) have better sustained handling procedures (extension, handling and freezing/thawing) than those contained in the ulterior part of a fractionated ejaculate (second portion of the sperm-rich fraction and the post-spermatic fraction, portion II). However, those studies were performed using pooled samples. In the present study, individual ejaculates were used. Split ejaculates (portions I and II) from five boars were frozen and thawed using a conventional freezing protocol, followed by computer-assisted motility and morphology analysis (CASA and ASMA, respectively), as well as an Annexin-V assay for spermatozoa from each boar and ejaculate portion. Significant differences between portions were observed in all ASMA-derived variables, except in one boar. Also significant differences were observed between boars and ejaculate portions in sperm quality post-thaw. We identified, however, boars showing best results of motility and sperm membrane integrity post-thaw in portion I, while in other boar the best results was observed in portion II. It is concluded that the identification of the ejaculate portion more suitable to sustain cryopreservation in each individual boar may be a readily applicable and easy technique to diminish variation in sperm freezability among boars.

Abnormalities of the hippocampus are similar in deoxycorticosterone acetate-salt hypertensive rats and spontaneously hypertensive rats

Hippocampal neuropathology is a recognised feature of the brain in spontaneously hypertensive rats (SHR), but similar studies are lacking in another model of hypertension, the mineralocorticoid-salt-treated rat. The present study aimed to compare changes in hippocampal parameters in 16-week-old male SHR (blood pressure approximately 190 mmHg) and their normotensive Wistar-Kyoto controls, with those of male Sprague-Dawley rats receiving (i) 10 mg deoxycorticosterone acetate (DOCA) every other day during 3 weeks and drinking 1% NaCl solution (blood pressure approximately 160 mmHg) and normotensive controls treated with (ii) DOCA and drinking water, (iii) drinking water only or (iv) 1% NaCl only. In these experimental groups, we determined: (i) cell proliferation in the dentate gyrus (DG) using the 5-bromo-2'-deoxyuridine-labelling technique; (ii) the number of glial fibrillary acidic protein (GFAP) positive astrocytes under the CA1, CA3 and DG; (iii) the number of apolipoprotein E (ApoE) positive astrocytes as a marker of potential neuronal damage; and (iv) the number of neurones in the hilus of the DG, taken as representative of neuronal density in other hippocampal subfields. Changes were remarkably similar in both models, indicating a decreased cell proliferation in DG, an increased number of astrocytes immunopositive for GFAP and ApoE and a reduced number of hilar neurones. Although hypertension may be a leading factor for these abnormalities, endocrine mechanisms may be involved, because hypothalamic-pituitary function, mineralocorticoid receptors and sensitivity to mineralocorticoid treatment are stimulated in SHR, whereas high exogenous mineralocorticoid levels circulate in DOCA-treated rats. Thus, in addition to the deleterious effects of hypertension, endocrine factors may contribute to the abnormalities of hippocampus in SHR and DOCA-treated rats.